Lamp supported reflector unit



Feb. 17, 1953 M. LIBERMAN LAMP SUPPORTED REFLECTOR UNIT Filed Jan. 5,1951 IA IVEN TOR- Mara/v L/BERMAN.

AIT'ORNE v4 7 size bulb intended to be used.

Patented Feb. 17, 1953 UNITED STATES PATENT OFFICE The present inventionrelates to a reflector unit for use with a conventional electric lightbulb.

In the field of display and advertising, use is made of an enormousquantity of spot and flood lamps. Many different types of units areutilized but one form in particular has achieved widespread use becauseof its simplicity. This form makes use of a specially designed lamphaving a portion of its bulb structure internally silvered and properlyshaped to make a combination lamp and reflector. Probably simplicity hasbeen its best selling point for it has many drawbacks. Of foremostconsideration is the high cost per lamp. In addition to this the entirelamp has to be replaced when the filament burns out. The reflectorportion, being integral with the lamp, is, of necessity, no longeruseful. The waste in material and in production costs is self-evident.

It is the purpose of the present invention to produce a reflector unitfor use with a conventional light bulb which will provide an assemblywhich is much more economical than the aforesaid special lamp and whichhas more eflicient light accumulating and directing properties as wellas providing for the use of filters, lenses, louvres, and the like.

The reflector unit is constructed to be supported by the bulb and isprovided with means for positioning it with respect to the bulb and itsfilament for proper focusing of the light rays. In one embodiment, thereflector is provided with a brightened matte finish as distinguishedfrom a specular finish, the matte finish resulting in new and improvedlight directing properties.

A different size reflector is provided for each Aside from differencesin size, the reflectors are in all other respects the same.

The basic reflector, where desired, can be provided with means forremovably positioning in the path of the directed light beam a lens ordiffuser, a louvre, colored filters or the like. The above items can beused singly or in combination.

In addition, the reflector is so constructed as to be insertable in theconventional bullet type lamp housing or in the recessed can type orhigh-hat fixture, Without making any mechanical or electrical changes,and regardless of the angle of inclination of the housing. The reflectorwill always retain its uniformity spaced relationship to the bulbwithout regard to the angularity of the bulb within the range of thewhole 360. The bulb and reflector, being yieldably coupled, anyvibration of the bulb is damped, thus contributing to longer life of thebulb.

Further advantages and feature will be apparent from the followingdetailed description taken in connection with the accompanyingillustrative drawings, in which:

Fig. 1 is an elevational view of an electric light bulb with myreflector applied thereto, the reflector being shown in cross-sectionand the relative locations of the sidewalls of a bullet and high-hatfixture being shown in phantom.

Fig. 2 is an enlarged fragmentary sectional view similar to Fig. 1, butshowing a modification thereof with a louvre and lens in place.

Fig. 3 is a fragmentary plan view of the bayonet lock used to secure thelouvre to the reflector in Fig. 2.

Fig. 4 is a fragmentary sectional view similar to Fig. 1, but showing amodification thereof.

Referring now to Fig. 1 of the drawing, there is shown at H! a standardclear type electric light bulb having the conventional glass envelope Hand internal filament [2. The bulb is usually pear-shaped and has abulbous body in which the filament is positioned below the cylindricalneck.

F It is provided with a threaded base l3 which is shown inserted in asocket [5 having an outwardly facing edge and which may be cylindricalas shown at I5a, or it may be provided with lugs as shown at [5b. Theparticular socket as well as the bulb construction forms no part of thepresent invention, being entirely conventional, and is shown merely byway of illustration. As will appear below, the invention is not limitedin its application to a clear bulb but is adapted for use with frostedand colored bulbs of common design.

The invention is predicated on the fact that the conventional bulbs onthe market are constructed according to standard specifications whereinthe filaments are located substantially the same distance from the basein each bulb of the same wattage. The various reflective surfaces of thereflector are so constructed and arranged as to have a givenrelationship with respect to the center 12a of the filament when thereflector is in operative position.

The reflector as shown in Fig. l is circular in horizontalcross-section, while it is composed of'a plurality of differently curvedsurfaces in the vertical plane. As shown, it is in operative position onlamp 10.

Taking the center 12a of the filament as a reference point, thereflector is provided with a spherical surface 22 having the radius RI.This surface extends from point 20, which lies in the same horizontalplane with filament l2, to point 2|. At point 2| the spherical surface22 connects with the cylindrical surface 23 which extends to a pointadjacent the neck of the lamp where it connects with a spherical zone25. Zone 25 has point [2a as a. center and is constructed with radiusR2. The portion of the reflector 21 from point to the outer edge 26 isparabolically formed with the focus at point [2a. Surfaces 22, and 21comprise the main operative reflective areas while cylinder 23 andcylindrical neck 30 serving primarily as interconnecting and positioningmedia, the reflective surfaces of the cylinder 23 and cylindrical neck30 contribute to the overall efllciency. Neck 30 is provided at its freeend with an inwardly extending flange 3|, the latter being covered witha suitable insulating material 32. of the socket 15 while neck 30 isconstructed so as to have approximately the same diameter as thestandard socket.

In order to maintain the reflector properly positioned on the lamp, aplurality of resilient finger elements are employed. One such ele mentis shown at secured near one end to the inside of neck 33 by a rivet 36.In preferred form three such fingers are employed equally spaced aroundthe reflector neck. But any number can be employed. The element 35 is aflattened .bl-ade-like member and is deflected to position 31 by thecurved portion 38 of the lamp 10 when the elements are in operativeposition. Thus positioned, the lamp [0 will also be yieldingly urgedoutwardly of its socket and henc more intimate electrical contact willbe had on the threads of the lamp plug. When the lamp is removed, thespring finger will assume the position 39 shown in dot-dash lines. Theother end of finger 35 is provided with an inwardly bent portion 40-covered with suitable insulating material 4|; The end 43 is alsoresilient and bears inwardly against the neck 45 of the lamp. It will beseen, therefore, that each finger 35 makes twopoint contact with thelamp, at points 46 and 41. The contact at point 41 serves to center theneck of the lamp with respect to the reflector. More accuratelyspeaking, the lamp is fixedly positioned in the socket and the reflectoris concentrically positioned about the lamp. The point of contact 46serves to center the outer portion of the reflector and cooperates withcontact point 41 to align the reflector axis with that of the lamp.Contact point 43 serves another function. It bearsagainst curved surface38 of the lamp and, as can be readily appreciated, develops a thrusttending to urge the reflector toward the base of the lamp into contactwiththesocket edge.

The reflector is installed as follows. With the bulb removed from thesocket, it is inserted into the reflector until the spring fingers 35 inrelaxed position 39 bear against the bulb at the base of the curvedportion as suggested by the dotdash outline of the bulb 53. Thereflector is then brought into contact with the socket I5 and the bulburged toward the socket and screwed therein. The reflector willautomatically locate itself about the bulb. Some persons might find itdesirable as an alternative method to slide the reflector toward thebulbous portion of the lamp so as to expose its base before engaging itin the socket. In this case, the springs will be deflected beyond theiroperative position wherein the fric- Ytion becomes greater than theaxial thrust and ,thus retains .the reflector high on the bulb.

Afterthe bulb is screwed into the socket, the re- As seen, theflangeabuts the edge flector need only be touched lightly to overcomethe friction, the fingers then snapping it into place against thesocket.

The location of points 2| and 24 are controlled by several factors. Itis necessary to provide clearance for the end 31 of finger 35 whilemaintaining surface 22 as extensive as possible for a given reflectorsize. It is also necessary to provide adequate free movement length forfinger 35. This latter factor, of course, is dependent upon theelasticity of the member 35 and the strength of the lamps glassenvelope. Naturally by proper choice, surface 25 can be shifted axiallywithin a wide range but I prefer to proportion my reflectorsubstantially as shown in Fig. l.

The outer edge 26 of the reflector is provided with a plurality ofspaced spring clip elements, one of which is shown at 5|. These aresecured to the reflector by any suitable means. The clips are utilizedto removably secure a lens or similar element 52 to the mouth of thereflector. Element 52 may be made of glass or other suitable materialand may be clear, frosted, colored or a combination of either to suitthe application.

In addition to performing the functions naturally flowing from itsmake-up, the element 52 acts as a cover for the reflector excluding dusttherefrom and, thereby changing the appearance of the entire unit ascompared with the bare reflector and lamp.

In order more effectively to prevent atmospheric deterioration of thereflective surfaces of the reflector, a rubber gasket 52a may beprovided between the reflector and the lens 52.

In certain installations, the embodiment shown in Fig. 2 may bepreferred. The construction is identical to that in Fig. 1, except thatthe parabolic portion 2! is extended and accelerated to the asymptoticcondition at point 30. It is then provided with a lateral offset 6|connecting with an apron 62. The offset and apron cooperate to form aseat for a louvre 63 provided with a bayonet lock 64, the details ofwhich may be more clearly seen in Fig. 3. The apron 62 is provided witha plurality of spring clips such as the one shown at 65, which clipsremovably support a lens 66. As with the embodiment of Fig. 1, the lens66 may be replaced by a frosted glass for diffusion or colored lenses orthe like. In addition, colored filters could be inserted adjacent thelouvre in an obvious manner.

Referring back to Fig. 1, there is shown by the phantom lines 55, therelationship of a bulletshape fixture with respect to the reflector whenthe latter is inserted in the former. Phantom lines 56 show therelationship when a can type fixture is employed. It is to be understoodthat these showings are merely for illustrative purposes.

With regard to both embodiments, it will be apparent that the twospherical reflecting surfaces tend to return most of the light raysemitted above the filament back to approximately point l2a. In a sense,this forms an effective point source of light. The parabolic portion ofthe reflector then converts the effective point source into a parallelbeam.

I have found that when the reflector is provided with a specular finishand it is employed with a clear bulb, it will, in the absence of adiffuser, project an image of the lamp filament on the surface to beilluminated. One way to correct this is to use a frosted glass forelement 52 or 66. But I have discovered a more efficient means. Insteadof providing the inner surfaces of the reflector with a specular finish,I provide them with a brightened matte finish. This suiflcientlydiffuses the light rays to eliminate the objectionable image whileretaining substantially the same reflective efiiciency. Of course, whenthe reflector is provided with a brightened matte finish, a diffusingglass may also be employed for further control. The matte finish isproduced by roughening the surface in any suitable manner as, forexample, using a roughened form upon which the reflector is spun. Theresulting surface is then brightened by electroplating or by the use ofa mild acid bath or by any other suitable process whereby the hills anddales in the surface are not materially altered although the surface isbrightened.

It will be seen that with my particular construction utilizing thespaced spherical zones 25 and 22, I am able to provide more reflectingsurface than if surface 22 were extended until it touched the lamp. Atthe same time, my construction makes it possible to use the springfingers for supporting the reflector in spaced re lationship from thebulb. This in itself is advantageous in reducing the amount of heatconveyed to the reflector. The surface 25 reflects the light raysprojected toward the base of the lamp, which rays are normally lost,back towards the filament where they are re-directed for usefulapplication. Surface 23 may be made reflective so as to re-direct anylight rays which travel a skew path.

A further modification is shown in Fig. 4 wherein a combination male andfemale electric plug element Ill of insulating material is integrallysecured to the reflector neck 30a by screw H, the flange 3la of thereflector embracing the shoulder of the combination plug. The resilientfingers 35a are in all respects similar to fingers 35 except that therear end of the fingers back of the rivet 36a is omitted. With thismodification the reflector, the plug element and lamp ll may be suppliedas a unit and may be so installed.

Thus there is provided by the present invention a highly eflicient,simple, inexpensive reflector adapted for use in connection with theordinary sockets and light bulbs.

Having described my invention in great detail, I desire to secure byUnited States Letters Patent and, therefore, claim:

1. In an electric lamp supported reflector unit adapted for display andadvertising purposes, the combination which comprises an electric lampsocket having an outwardly-facing edge, a pearshaped electric lampscrewed into said socket and having a bulbous body with a lightingfilament at approximately the center thereof and a substantiallycylindrical neck, and a reflector closely surrounding said electric lampand having an end held against the edge of said socket, said reflectorhaving at said end a short cylindrical neck with a narrow diameterclosely surrounding the neck of said lamp, an elongated cylindricalreflecting zone spaced axially from said short neck and surrounding theneck of the bulb to a region adjacent to the junction with the bulbousbody, a narrow annular reflecting zone joining said neck and saidcylindrical reflecting zone and reflecting light rays coming from saidfilament, a parabolic reflecting zone with a wide mouth and a narrowbase, a spherical reflecting zone connecting said narrow base of saidparabolic reflecting zone and the end of said cylindrical reflectingzone, and means for holding said short neck against the edge of thesocket and for holding the said reflecting zones in close spacedrelationship with said supporting electric lamp.

2. In an electric lamp supported reflector unit adapted for display andadvertising purposes, the combination which comprises an electric lampsocket having an outwardly-facing edge, a pearshaped electric lampscrewed into said socket and having a bulbous body with a lightingfilament at approximately the center thereof and a substantiallycylindrical neck, and a reflector closely surrounding said electric lampand having an end held against the edge of said socket, said reflectorhaving a flange at said end having a covering of insulating material andadapted to abut the edge of said socket, a substantially cylindricalshort neck at said end of the reflector extending substantially parallelto and closely surrounding the neck of said electric lamp, a shortcurved zone extending from said neck for a short distance to provide anannular reflecting zone for reflecting light rays coming from saidfilament, a cylindrical reflecting zone joined with said short curvedzone and extending to a region close to the bulbous body of said lamp, aspherical reflecting zone extending from said cylindrical surface andhaving its center coincide approximately with the center of the saidbulbous body, a parabolic reflecting zone extending from said sphericalreflecting zone at a region approximately on line with the filament ofsaid lamp to a region in alignment approximately with the front of thesaid bulbous body, three short resilient fingers secured at equi-spacedpoints to said neck and having the free ends thereof covered withinsulating material and ada ted to press against the neck of said lampin front of the edge of said socket, and three resilient flattenedblade-like members mounted inside of said reflector at equi-spacedpoints and adapted to press against the said bulbous body and yieldinglycouple the reflector and force it against the edge of the said socketwhereby the reflector will automatically locate itself about the saidsupporting electric lamp and will be concentrically positioned about thefilament for proper focusing of light rays and for reflection of a majorportion of said rays.

3. In an electric lamp reflector unit adapted for display andadvertising purposes, the combination which comprises an electric lampsocket, a pear-shaped electric lamp screwed into said pocket and havinga bulbous body with a lighting filament at approximately the centerthereof and a substantially cylindrical neck, and a reflector closelysurrounding said electric lamp and held in proper focusing relationship,said reflector having an elongated reflective cylindrical surfaceadapted to surround the neck of said electric lamp, a sphericalreflective surface joined to the one end of said cylindrical surface andto form a portion of a sphere surrounding and being close to the upperpart of the bulbous body of said electric lamp, a narrow annular curvedreflective surface joined to the other end of said cylindrical surfaceand extending laterally close to the neck of said lamp to reflect lightrays emitted by said filament outwardly, a parabolic reflective surfacejoined to the end of said spherical reflective surface to reflect lightrays coming from said lamp, and means for holding the aforesaidreflective surfaces of the reflector in close spaced relationship withsaid electric lamp.

4. In. an electric lamp reflector unit, the combination which comprisesan electric lamp socket, a pear-shaped electric lamp mounted in saidsocket and having a bulbous body with a lighting filament atapproximately the center thereof and a substantially cylindrical neck,and a reflector closely surrounding said electric lamp, said reflectorhaving a wide mouth parabolic section terminating adjacent the front ofthe bulbous body of said electric lamp and receding back to near thecenter of said bulbous body, a spherical section joining said parabolicsection and receding in substantial conformation with said bulbous bodyto a region adjacent the junction with the lamp neck, a recedingcylindrical section joining the spherical section and extendingsubstantially parallel with the neck, and another spherical sectionjoining said cylindrical section at a region closely adjacent the neckof the bulb whereby substantially all of the light rays coming from theelectric lamp are reflected forwardly.

5. In an electric lamp supported reflector unit, the combination whichcomprises an electric lamp socket having an outwardly-facing edge, apearshaped electric lamp mounted in said socket and having a bulbousbody with a lighting filament at approximately the center thereof and asubstantially cylindrical neck, and a metal reflector closelysurrounding said electric lamp and held against the outwardly facingedge of the socket, said reflector having at said end a shortcylindrical neck with a narrow diameter closely surrounding the neck ofsaid lamp, an elongated cylindrical reflecting zone spaced axially fromsaid short neck and surrounding the said neck of the bulb to a regionadjacent to the junction of the bulb neck and the bulbous body, a narrowannular spherical reflecting zone joining said neck and said cylindricalreflecting zone and having a radius with a center substantiallycoincident with the center of said electric lamp to reflect light rayscoming from said filament, a parabolic reflecting zone with a wide mouthand a narrow base, a spherical reflecting zone connecting said narrowbase of said parabolic refiecting zone and the end of said cylindricalreflecting zone and having a radius with a center substantiallycoincident with the center of said electric lamp, and a brightened mattereflective surface covering the aforesaid reflecting zones and adaptedto effectively reflect light coming from said electric lamp.

6. In an electric lamp supported reflector unit, the combination whichcomprises an electric lamp socket having an outwardly-facing edge, apear-shaped electric lamp mounted in said socket and having a bulbousbody with a lighting filament at approximately the center thereof and asubstantially cylindrical neck, and a reflect cioseiy surrounding saidelectric lamp and held against the outwardly facing edge of the socket,said reflector having an elongated reflective cylindrical surfacesurrounding the neck of said electric lamp, a spherical reflectivesurface joined at one end to the said cylindrical surface and forming aportion of a sphere surrounding and being close to the upper part of thebulbous body of said electric lamp, a narrow annular curved reflectivesurface joined to the other end of said cylindrical surface andextending laterally close to the neck of said lamp to reflect light raysemitted by said filament outwardly, and a parabolic rcliective surfacejoined to the end of said spherical reflective surface to reflect lightrays coming from lamp.

IVIILTON LIEERMAN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNZTED STATES PATENTS Number Name Date 1,016,223 Ifland Jan. 30, 19121,711,473 l-Ialvorson, Jr Apr. 30, 1929 1,753,209 Laib Apr. 8, 19301,918,434 Naysmith July 18, 1933 1,939,525 Daumen Dec. 19, 19332,437,522 Handler Mar. 9, 1948 FOREIGN PATENTS Number Country Date535,694 Great Britain Apr. 18, 1941 615,778 France Jan. 17, 1927 OTHERREFERENCES Publication, Lighting by Century, pages 28 and 29, receivedin this oifice April 1'7, 1941.

